When software developers discover a problem in a computer program (such as an operating system kernel), they typically create a patch to fix the problem. A patch is an arbitrary source code modification to the computer program, and it can result in changes to many functions within the computer program. Automatically determining what computer program functions are changed by an arbitrary source code modification can be useful for many software processes, such as determining how to “hot update” a computer program (i.e., apply a source code modification to a running program without restarting the program).
Determining which computer program functions are changed by a source code modification is an important task that a hot update system must accomplish. Prior hot update systems determined which functions changed as a result of a source code modification at the source code layer, and thus were subject to a number of limitations (for example, they do not handle function inlining or implicit casting correctly).